What is a family preference category? Qualified relatives of a U.S. citizen or permanent resident who are not known as an immediate relative may have to wait for a visa to become available before they can apply for permanent residency. These categories are known as Preference Categories and include:
Sedimentary rocks are formed by sediment that is deposited over time, usually as layers at the bottom of lakes and oceans. This sediment can include minerals, small pieces of plants and other organic matter. The sediment is compressed over a long period of time before consolidating into solid layers of rock. Sedimentary rocks forms layers called strata which can often be seen in exposed cliffs.
   Sedimentary rocks can also be formed when minerals are dissolved in  water and are then resolidified. This type of sedimentary rock is  called a chemical sedimentary rock.Oolitic limestone is a good  example of this type of sedimentary rock. 1 person found this useful. sedimentary rock is one made up of particles of minerals that have settled out of water or wind in layers that have been subsequently lithified. Think of mud settling at the bottom of a lake, this is a sedimentary deposit.